Pit-type electric elevator



. 8, 1953 H. J. HULSART PIT-TYPE ELECTRIC ELEVATOR Filed Aug. 21 1950 INVENTOR ATTORNEYS.

level, and which will automatically realign itself I.;STATE PATfEi ,PITL-TYPEELECTRIIG r. Ar a T An l s Anna a a 1' Claim. (01. is

" Ihis' invention-relates to a compact -pit-Wine invention 'as'"it-appears electricelevatonfor. use in'm'anufacturingplants and ready fo 'iu'se'. (FI andsimilar locations; forlowering materials into --'-Fig;2*is an enlarged: secti n n:1ine z. 'z of a pit for thepu loose of keeping the top'ofjthe Fig. I. fl

' 3 is "an enlarged sctionon--line' 3-:' -3 of "when mounted" i a pit load 'at 'a conv'enientheight for workers, and to Fig: enabl fioor tru cks and skids to handle higher Fig-2 g 1 Fig2J4;isa section onlinen oerigiz By wayg of' bafii rollnd, it may be noted that r:. ':"Fig;"5 i'sa's'ection'on line :5 of FiguBfl electrically, mechanically, or hydraulically aotu- Referring to theadraw-in'gs'in detail, formed in ated elevators have been utilized in similar cirthe ground surface G is a :pit-EE;in' 'the central cumstances, but in general, have had certain disportio'n'of-which-is'duga.well'W; J V i' '9;

advantages. For example, in many instances a -Sunk'in the wel1.-W'is a" cylindrical casing" l certain amount offfixed lifting apparatus is re- 'open atvits;upper-endr iA'plurality of circumquiredabove the floor level. In other instances ferentially"spaced-inwardly"extending pairs-"of it-isn'ecessary that tubing ,orlpipe members be roller; brackets 2- are mountedin' thegup'per end machined, as in the case"6f'hydraulic lifts, and in of said casingdand extend radially and inwardly general, the cost of these devices has been rather from the]; W311l '0fjfthe.'.'.Ca-Sing; :Rollers 3 .are. carhigh. ried by these brackets and comprise guide rollers An important object of the present invention, rollably engaging the vertically reciprocable tubuaccordingly, is to provide an elevator of the charlar piston 4 having up and down movement in acter described which can be manufactured at the outer casing. A load-supporting platform 5 considerably less cost than other elevators, while is mounted upon the upper end of the piston 4 still being adapted to support loads of the same within the pit P, and is adapted to support a weight as said other elevators, and without reducload of selected material, not shown.

tion of over-all efliciency. Adjacent its lower end, the piston 4 is pro- Another important object is to provide a pitvided with a circumferential series of spaced type elevator construction of the character depairs of roller brackets 6 provided with rollers l.

scribed which is so designed as to permit any of The brackets 6 are secured to the exterior surface various conventional lifting means to be utilized of the piston wall, and extend radially and outtherewith, as for exampl a motor and winch wardly therefrom towards the wall of the outer unit, gear rack and pinion, or threaded shaft casing, the rollers I having rollable contact with or feed screw. the casing wall.

Another importa t object iS to provide a p By reason of this arrangement, it may be noted ype elevator of the character indicated which that in any position of vertical adjustment of the will, when lifted by means of a cable or chain, piston 4, it is retained in a prescribed position be capable of rotation as to its load supporting within the outer casing I. platform, to some extent when above the ground At its lower end, the piston 4 has rigidly mounted thereinthe coaxia bear with the plt for lowering Without the necessity which is journaled a shaft 9 on wiiili ifi iitibi of antirotating devices such as are required in a pulley In. The lower end portion would be connection wlth ot er ype f elevators now in provided with diametrically opposed vertical slots use for slm lar purposes, Such as Single-piston accommodating said pulley, as will be readily hydraulic pit-type lifts. appreciated.

With the fore oing and other bjects in view At the upper end of the casing I there is which will pp ar s h description proceeds, mounted an eye H in which is secured one end the invention consists of certain novel details of of a rope or cable l2 that extends downwardly construction and combinations of parts hereinin the space between the piston and the casing after more fully described a d point d t in the wall and passes around the pulley Hi the cable claim, it being understood that chang s may be then passing up the space between the piston and made in the construction and arrangement of casing wall, and being trained over a sheave l3 parts without departing from the spirit of the rotatably mounted as at M in a housing 15 sunk invention as claimed. in the pit P. Mounted in said housing are an Referring to thedrawmgs electric motor l6 and winch unit I! used for wind- Figure 1 IS a side elevat1ona1 view of a piting and unwinding the cable I2 for elevation or type elevator formed in accordance with the lowering of the platform 5.

Although on form of lifting means is illustrated in the drawings, namely a winch means, I believe that other means for elevation or lowering of the piston can also be utilized, for example, a rack and pinion, with the pinion being mounted in the position of the sheave of the present example, and with the rack being secured vertically to the exterior surface of the piston 4. Or, a screw can be mounted upon the external surface of the piston cylinder "4, to be engaged 'with a follower rotated by the motor within the housing.

The cable arrangement does have the advantage, however, of permitting partial rotation of the platform 5 when it is elevated above the ground surface G, and when released after said partial rotation, the platform 5 will automatically realign itself with the pit, by the pull of the cable l2, which will have been twisted somewhat out of position when the platform was rotated. The tendency of the cable to return from the spiral position to which it would have been moved to a position in which it is fully vertical will automatically serve to realign the parts of the apparatus in the position illustrated in Fig. l.

The device has particular important chemoteristics in respect to its comprising a compact pit-type electric elevator, capable of manufacture at far less cost than conventional electric or hydraulic elevators now in use;

What is claimed is:

A pit-type elevator construction comprising an outer casing adapted to be sunk into a well extending downwardly below the bottom surface of a ground pit, a plunger disposed within said casing and vertically movable up and down therew'ithin, guide rollers carried by the plunger for maintaining the same in proper spaced relation to said casing, a platform carried by the upper end of said plunger and rigidly secured thereto and normally disposed within said pit below the ground level, a pulley carried by the lower end of said plunger and having its periphery extending below said plunger and beyond the opposite sides thereof, a guide sheave mounted adjacent the upper end of said casing and having its periphery projecting into said casing, a flexible cable secured to said sheave and attending around the pulley and attached to said casing adjacent the upprer end thereof, means for rotating said sheave to raise and lower said plunger and platform, the peripheral edges of said pulley and sheave being disposed in vertical alignment, spaced guides carried by said casing and engaging said plunger but permitting partial rotation of saidplatform when it is moved above ground level, the plunger and easing being so spaced with respect to each other and with respect to the rollers and guides as to permit said partial rotation of said platform and the proper realignment of parts as the platform is returned to nor mal position by rotation of said sheave.

HAROLD J. HULSART.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,902,820 an 2a, 1933 2,137,743 strass'man Nov. 22, 1938 FQREIGN PATENTS Number Country Date I 4 748,082 France Apr. 10, 1933 

